Introduction. Rambutan (Nephelium lappaceumL.) is a kind of tropical fruit with high commercial value ininternational trade. However, harvested rambutan fruits suffer from ashort shelf life and show rapid postharvest deterioration problems dueto spintern browning and flesh decay. Materials andmethods. Rambutan fruit (cv. ‘Baoyan 5’) were harvestedin 2009 and 2010. Changes in some chemical components and thephysiology of fruits were investigated at different storagetemperatures (25 °C and 10 °C) and with different packing materials(regular low-density polyethylene and anti-moisture polyethylenebags). Results and discussion. Changes in the developmentof the browning index, and contents of total soluble solids,titratable acidity and vitamin C greatly decreased during lowtemperature storage (10 °C); moreover, low temperature storage (10 °C)could maintain a significantly higher level of superoxide dismutaseactivity and lower values of malondialdehyde and cell membranepermeability. The effects of packing material were different accordingto the different storage temperatures. At 10 °C, the beneficialeffects of anti-moisture polyethylene bags on fruit quality andphysiology were observed. However, at 25 °C, fruit packed with regularlow-density polyethylene proved to be of better quality than thosepacked with anti-moisture polyethylene bags. Conclusion.The overall results suggest that packing with anti-moisturepolyethylene bags and storage at 10 °C were the most suitableconditions to maintain quality and to extend the storage life oframbutan fruit.

Introduction. Rambutan is a tropical fruit species with recalcitrant seeds. Despite the expansion of exotic fruit cultivation in Brazil, lots of which fruit species, including rambutan, need basic information, especially in relation to propagation and storage of seeds, which are important for genetic improvement studies, maintenance of genetic sources and seedling production. Materials and methods. A completely randomized design was adopted with treatments distributed in a factorial arrangement, 3 × 4, referring to three seed storage conditions [room temperature conditions; a dry chamber with (18 ± 2) °C and 60% relative humidity; and a cold chamber with (10 ± 2) °C and 70% relative humidity] and four storage times (0, 7, 14 and 21 d). Each treatment of 10 seeds was replicated five times. Data on seedling emergence, emergence rate, plant height, number of leaves and length of main root were submitted to variance analysis and means were separated using Tukey’s test. Correlation analysis between seed moisture and seedling emergence was performed. Results and discussion. Our results indicated that dry chamber conditions promoted the statistically significantly highest seedling emergence after 7 d of storage. Cold chamber conditions promoted an extremely low seedling emergence independently of time. Conclusion. Rambutan seeds can be stored in a dry chamber for 7 d without losing viability; after 14 d of storage the loss of emergence is 60%.

This study examined the hypothesis that desiccation sensitivities of recalcitrant and intermediate seeds can be categorized into discrete levels of critical water potential. The equilibrium dehydration method was used to determine the critical water potential (CWP) below which desiccation damage started to occur. The CWP values of Bruguiera cylindrica, Lansium domesticum, Litchi chinensis and Lumitzera racemosa are approximately –4 MPa. The CWP values of Andira inermis, Avicennia alba, Castanea sinensis (from New Zealand), Citrus aurantifolia, Ginkgo biloba, Nephelium lappaceum and Theobroma cacao (immature axis) are approximately –8 MPa. The CWP values of Acer pseudoplatanus, Castanea sinensis (from China), Quercus rubra and Theobroma cacao(mature axis) are approximately –12 MPa. The CWP values of Artocarpus heterophyllus and Hevea brasiliensis are approximately -23 MPa, while the CWP values of Acer platanoides, Azadirachta indica, Carica papaya and Coffea arabica are approximately –73 MPa. Together with data available in earlier literature, these CWP values suggest that there are five discrete levels of critical water potential among desiccation-sensitive seed tissues. These data support the hypothesis that discrete levels of desiccation sensitivity occur among recalcitrant and intermediate seeds, and suggest that specific damaging and protective mechanisms exist at certain hydration levels.

Introduction. In Mexico, the rambutan is not a well-known fruit tree, but it has great potential for its establishment and development in the Soconusco region because of the local good agro-ecological conditions for the production of its fruit. Currently, there are already 200 ha of plantations in the region with a good adaptation and a rewarding yield. Rambutan history, cultivation practices, post-harvest operation and commercialisation in the Soconusco region were studied to identify the possibilities of an expansion of the species. In particular, the work aimed at identifying different varieties inside the rambutan orchards. Materials and methods. Four areas were studied from a survey in 14 farms. Different parameters of fruit quality were analysed (ten trees sampled per farm): fruit diameter, fruit length, rind colour, spintern appearance, aril diameter, aril length, aril weight, flesh colour, flavour, succulence, adherence of flesh, and presence of pests and diseases. Results. Fruit quality was dissimilar for the four studied areas. Among the different fruit samples collected, it appeared that the environment and cultivation management play an important role in fruit size. The diversity of varieties planted in the different sites was determined by clustering analyses. Independent of their site of origin, at least six well-defined cluster classes could be identified. Conclusion. Fruit weight, spintern appearance and colour, as well as fruit diameter and aril to fruit weight appeared to be good indicators to identify fruit quality. The clustering analyses showed that there is a wide range of overlapping varieties to be found in the Soconusco region. Six major varietal groups were identified. Further varietal differentiation and characterisation of rambutan in the Soconusco region will be necessary for a better establishment of this fruit tree crop.